[1625] On one occasion the Blessed One was dwelling at Bārāṇasī, in the Deer Park at Isipatana. Then the lay follower (upāsaka) Dhammadinna, together with five hundred lay followers, approached the Blessed One; having approached and paid homage to the Blessed One, he sat down to one side. Sitting to one side, the lay follower Dhammadinna said this to the Blessed One: "Venerable sir, let the Blessed One exhort us; venerable sir, let the Blessed One instruct us in that which would be for our welfare and happiness for a long time."
"Therefore, Dhammadinna, you should train thus: 'From time to time we shall enter upon and dwell in those discourses spoken by the Tathāgata that are deep, deep in meaning, supramundane (lokuttara), connected with emptiness (suññatā).' It is thus, Dhammadinna, that you should train."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.